Forget about gigabytes and terabytes. Many corporations, banks, government agencies and scientific research institutions now handle petabytes of information, and the data storage technology that has served us well for a generation is starting to creak like a schooner in a hurricane.

We’re talking about the humble hard-disk drive, standard equipment for PCs since the 1980s. Today, big-data centers still rely on hard drives—actually hoards of them in vast arrays, like
NetApp's flagship enterprise storage system, which can employ as many as 1,440 drives to store more than 4 petabytes. Why so many drives? Because the biggest conventional hard drives currently hold "only" a few terabytes, and a petabyte is 1,000 times larger than a terabyte. Do the math.

It gets worse. The capacity of hard drives isn't increasing fast enough to keep up with the explosion of digital data worldwide. Forecasts call for a 50-fold increase in global data by 2020, but hard drives may grow only by a factor of 15, even with new technology that allows more data to be crammed onto each square inch of a disk.

So far, no storage technology has been developed that can scale up to the petabyte and beyond, but the hunt for new solutions has produced some intriguing—and even outlandish, possibilities. Here are a few.

Bacteria

You read that right. Students at the Chinese University of Hong Kong figured out how to store encrypted data in the DNA of E. coli bacteria. Such "biostorage" could be used for text, music, video—you name it. A single gram of the bacteria could hold as much as 450 conventional 2-terabyte hard drives. And since the bacteria keep replicating, the data could last for thousands of years. You just have to make sure to keep your data off your food.

Diamonds

They're not just for jewelry. Researchers at Harvard, the Max Planck Institute of Quantum Optics and Caltech were able to store a quantum state in a diamond crystal for more than second, at room temperature. Doesn't sound like much, but in quantum physics, that's a lifetime, and a big step toward building a quantum computer.

Respected science fiction author Charles Stross has proposed using nanotechnology to produce synthetic diamonds, with carbon-12 and carbon-13 atoms stacked so they can serve as binary switches. Stross figures that 25 grams of such material would be enough to store a compressed video recording of everything seen by every person in a country the size of Germany for six years. With 600 grams of diamond memory, you could hold the lifelogs of everyone on Earth for a year.

Matrioshka Brain

This one—from the late scientist Robert Bradbury (not Ray Bradbury)—is a bit farfetched, but the payoff is titanic. He envisioned a megastructure of multiple spherical shells around a star, using its energy to fuel almost unlimited computational power. The shells, nested like Russian Matrioshka dolls, would be composed largely of nano-scale computers made from "computronium," which could be almost any matter. In his novel "Accelerando," Stross describes a Matrioshka brain around our sun, fashioned from the debris of inner planets that have been pulverized (not Earth).

A Matrioshka brain could be used to manage the global economy, predict weather down to the minute, and store not just everyone's actions and words, but human minds themselves in virtual reality. Try that with a hard drive.